The cell cytoskeleton and the cell nucleus: A tale of two interacting active environments

The cell nucleus is very much an active environment with molecular motors such as RNA polymerase, helicase, and topoisomerase all manuevering to facilitate DNA transcription. The cell cytoskeleton is also an active environment with molecular motors such as myosin, kinesin, and cytoplasmic dynein working to give the cell shape and rigidity. On the other hand, the underlying backbone of the active environment of the cell nucleus is a single, compacted polymer, i.e. DNA, while for the cell cytoskeleton, it is a composite semiflexible polymer network involving actin, microtubules, and intermediate filaments. It turns out that these two active environments are not independent of each other and are, not suprisingly, mechanically coupled via LINC complexes, though details of the coupling remain poorly understood. We, therefore, computationally study the shape of the interface between these two active environments as a function of the nature of their mechanical coupling to ultimately work towards a framework for quantitative prediction of nuclear shape fluctuations in cells.